Niemann-Pick type C: a potentially treatable disorder?

Niemann-Pick disease refers to a group of autosomal recessive lipid storage disorders associated with a variable degree of neurological manifestations in addition to other organ involvement. Niemann-Pick disease is divided into types A-C. Of interest to neurologists is Niemann-Pick type C because of the association with neurological manifestations that are not confined to childhood. The clinical presentation of Niemann-Pick type C is variable, depending on age at onset. Neurological symptoms vary with age: hypotonia, delay in developmental motor milestones, falls, seizures, learning difficulties, ataxia with cognitive deficits and psychosis. The definitive diagnosis of Niemann-Pick type C requires demonstration of abnormal intracellular cholesterol trafficking using the filipin test. Therapeutic interventions are few but one that is of interest is miglustat, which has been approved for specific treatment of the neurological manifestations. It showed improvement in horizontal saccadic eye movement and a trend towards improvement or stabilisation in swallowing, hearing and walking. Niemann-Pick type C should be considered in patients with early-onset ataxia associated with progressive learning/cognitive difficulties even in the absence of vertical gaze palsy.